- Equations
- Numerical Evaluation

Summary: This module is from Elementary Algebra by Denny Burzynski and Wade Ellis, Jr. Operations with algebraic expressions and numerical evaluations are introduced in this chapter. Coefficients are described rather than merely defined. Special binomial products have both literal and symbolic explanations and since they occur so frequently in mathematics, we have been careful to help the student remember them. In each example problem, the student is "talked" through the symbolic form. Objectives of this module: understand the meaning of an equation, be able to perform numerical evaluations.

- Equations
- Numerical Evaluation

An equation is a statement that two algebraic expressions are equal.

An equation is composed of three parts.

Each of the boxes represents an algebraic expression. An equation consists of two expressions separated by an equal sign. The equal sign makes the statement that the two expressions are equivalent, that is, they represent the same value. For example:

The equation expresses the relationship between the variables

The equation expresses the relationship between the variables

Numerical evaluation is the process of determining a value by substituting numbers for letters.

In various areas (business, statistics, physics, chemistry, astronomy, sociology, psychology, etc.), particular equations occur quite frequently. Such equations are called formulas. Numerical evaluation is used frequently with formulas.

This chemistry equation expresses the relationship between the pressure

*On the Calculator*

This statistics equation expresses the relationship between the variables

*On the Calculator*

This equation expresses the relationship between

*On the Calculator*

192

40

50

13

For the following problems, observe the equations and state the relationship being expressed.

Use numerical evaluation on the equations for the following problems.

Geometry (circumference of a circle)

Geometry (area of a rectangle)

Electricity (current in a circuit)

3

Electricity (current in a circuit)

Business (simple interest)

360

Business (simple interest)

Geometry (area of a parallelogram)

96

Geometry (area of a triangle)

Geometry (perimeter of a rectangle)

8

Geometry (perimeter of a rectangle)

Geometry (perimeter of a rectangle)

Physics (force)

Physics (force)

448

Physics (force)

Physics (force)

Physics (momentum)

Physics (momentum)

396

Physics (momentum)

Physics (energy)

150

Physics (energy)

Physics (energy)

Astronomy (Kepler’s law of planetary motion)

Astronomy (Kepler’s law of planetary motion)

Astronomy (Kepler’s law of planetary motion)

(*Hint:* On the calculator, Type 5.1, Press

Astronomy (Kepler’s law of planetary motion)

Business (profit, revenue, and cost)

Business (profit, revenue, and cost)

650

Geometry (area of a circle)

Geometry (area of a circle)

(*Hint:* The number 10 that occurs on the display a few spaces away from the other number on the display is the exponent of 10 in the scientific notation form of the number.)

An object travels on a horizontal line. The distance it travels is represented by

Determine the distance traveled by the object if it has been in motion for 6 seconds.

In medicine, there are several rules of thumb used by physicians to determine a child’s dose,

where

6 units

A hemispherical water tank of radius 6 feet has water dripping into it. The equation relating the volume,

The equation

blue whales are considered immature. At birth, a blue whale is approximately 24 feet long. Determine the weight of a blue whale that measures 83 feet in length.

A relationship exists between the length of a cantilever beam and the amount it is deflected when a weight is attached to its end. If a cantilever beam 20 feet long has a 600 pound weight attached to its end, the equation relating beam length and amount of deflection is

where

There is a relationship between the length of a suspension bridge cable that is secured between two vertical supports and the amount of sag of the cable. If we represent the length of the cable by

*((Reference))* simplify

*((Reference))* simplify

*((Reference))* Find the value of

*((Reference))* For the expression

*((Reference))* How many

Comments:"Reviewer's Comments: 'I recommend this book for courses in elementary algebra. The chapters are fairly clear and comprehensible, making them quite readable. The authors do a particularly nice job […]"